From the EP 1 863 927 A1 a swivel table is known, having a lower housing and a table top. The table can be moved from a stowed position, in which the table top is disposed substantially vertically in the lower housing into a use position, in which the table top is disposed substantially horizontally above the lower housing and is supported by this. Pulling the table construction out of the lower housing is assisted by springs (not shown).
In particular, what is disadvantageous in the known embodiments of folding tables for aircraft is that the assistance of the deploying motion is solved insufficiently.
In the prior art (cf. e.g. DE 19 09 998), in particular a rack-and-pinion gear is proposed, by means of which lifting of the table top on opposite sides is performed in a synchronized manner. The rack-and-pinion gear interacts with a spring, assisting the deployment of the table top. Said drive mechanism, however, has a number of disadvantages. First of all, the known design requires much space, which runs counter to the effort made by the manufacturer in achieving the largest possible space for passengers. Another disadvantage is the comparatively high weight of the rack and pinion gear. On the other hand, in the aircraft industry various efforts are being made to reduce the weight of the assembled components to the effect of reducing the fuel required. In addition, the noise generation when deploying the table was found to be disturbing at times. Furthermore, in the prior art power assistance during the deploying process is not uniform for the entire deploying process.
In addition, in the prior art other embodiments of adjustable tables are known.
The DE 199 35 762 A1 describes a retractable and extendable link plate for cantilever supports. Due to the positive and non-positive connections of the individual segments the link plate is extendable at any given angle. The risk of injury of the user due to abrupt collapse is to be prevented. For extending the link plate a drive is provided which is connected to a spindle via driving wheels and a driving belt, with which spindle a strut and tie bar is actuated. In addition, a cable pull is provided, however, which is designed for tightening the links only.
The US 2010/171350 A1 describes a seat with a pivoting display screen which can be stowed on the side of the seat by means of a rail. The displacement mechanism comprises driving rollers. In addition, a cable pull is provided as part of a dampening device.
The WO 2008/141829 A1 relates to a table apparatus for a vehicle seat, the table apparatus comprising a support mechanism and at least a table top. When not in use, the table apparatus can be stowed essentially horizontally via a rod arrangement.
Accordingly, the invention is based on the object to reduce or obviate the disadvantages of the prior art. Therefore, in particular, the object of the invention is to improve the folding table of the above stated type by means of constructionally simple means to the effect that the space required for the displacement and folding mechanism is reduced and at the same time a reduction in weight is achieved, in which connection noise generation is reduced and the deploying process is to be supported in an easy, uniform and reliable manner.
Said object is solved by a folding table having the features of claim 1. Preferred embodiments are given in the dependent claims.
According to the invention, the drive device comprises a linear drive element which is connected to the displacement device via a cable pull device.
Accordingly, the force transmission between the linear drive element and the displacement device for the support device is effected by means of a cable pull device. The cable pull device comprises at least a traction cable, which on the one side is connected to the linear drive element and on the other side is connected to the displacement device. By actuating the linear drive element a tensile force is applied onto the displacement device via the cable pull device, by means of which the displacement device is displaced together with the support device for the table top to the deployed position. Then, the support element can be folded by means of the folding device, so that the folding table is available in the use position. The design according to the invention has a number of advantages as against the prior art. For one thing, the cable pull device can be accommodated inside the frame in a particularly space-saving manner. Another advantage is that the driving force can be deflected in a particularly simple manner by means of the traction cable, whereby the spatial conditions in the mounting space can be utilized in an optimal manner. Furthermore, the weight of the drive device can be reduced, thus achieving a reduction of the amount of fuel needed in aircrafts. In addition, it is advantageous that the driving noise can be reduced, thus giving the user a particularly high-quality impression.
To achieve a reliable, stable and low-noise design it is favorable if as a linear drive element a gas (compression) spring comprising a piston element is provided, whose forward motion is transferable onto the displacement device via the cable pull device. The construction of such gas springs is generally known in the prior art, so that this does not have to be dealt with in detail. The gas spring comprises at least a cylinder element and a piston element movable in relation thereto, whereby the piston element can be moved by the pressure of a compressed gas in the extending direction. The displacement of the piston element is transmitted onto the traction cable of the cable pull device, so that a tensile force is applied onto the displacement device. For this purpose, the free end of the piston element can be connected to the frame, whereas the cylinder element is supported movably together with the corresponding end of the traction cable. Of course, however, the cylinder element might also be connected to the frame, in this case the traction cable being coupled to the piston element. In this embodiment it is particularly advantageous that the gas spring can be arranged on the frame in a particularly space-saving manner. In addition, it is advantageous that a dampening mechanism can be integrated in a simple manner. It is particularly preferred that the gas spring is connected to a release device. By actuating the release device the piston element is extended out of the cylinder element of the gas spring. Actuation of the gas spring can be effected by means of a pressure lock (“touch latch”). In this connection, the displacement mechanism is locked upon pressing down the displacement device or the table top and unlocked again upon renewed pressing. Accordingly, the pressure lock is lockable upon moving the folding table into the stowed position by pressing down the support device or the table top. In the stowed position, the pressure lock is unlockable by a pressure on the support device or the table top, whereby the folding table can be moved into the deployed or use position with the aid of the drive device. Such pressure locks or “touch latches” are known in the prior art, however only in the case of other devices such as doors of electric appliances or furniture. In the deploying process the linear forward motion of the piston element is transferred onto the one end of the cable pull, which lifts the displacement device for the table top with the other end. After end of use, the support device with the table top is folded up and moved to the stowed position, whereby the gas spring is compressed with the aid of the dead weight of the table top as well as the support, folding and displacement devices.
To move the support device for the table top along a given track between the stowed position and the deployed position, it is favorable if the displacement device each comprises a guide device on opposite sides of the frame, whereby the guide devices are each connected to a traction cable of the cable pull device. Due to the arrangement of the guide devices on opposite sides of the frame the support device for the table top is held and guided on both sides, whereby the deployment movement is effected in a particularly reliable and easy manner. Preferably, the drive device comprises exactly one linear drive element, in particular exactly one gas spring, which is coupled to exactly two cable pulls for the opposite guide devices. The two cable pulls are preferably arranged such that the forward motion of the linear drive element is converted into identical displacements of the displacement devices on the opposite sides of the frame. For this purpose, on the one hand, the cable pull device can comprise rolls movable with the linear drive element and, on the other hand, rolls arranged immovably on the frame, whereby the cable pulls are each guided over a roll movable with the linear drive element and the roll arranged immovably on the frame.
To displace the displacement device in a reliable and low-noise manner between the stowed position and the deployed position, in a preferred variant of embodiment it is advantageous if the guide devices each comprise a guide carriage, which is movable in a corresponding guiding groove. The cable pulls of the cable pull device interact with the guide carriages arranged at opposite sides of the frame, on which guide carriages the support device for the table top is installed.
According to a particularly preferred embodiment it is provided that the guide devices each comprise a guide rail connected to the frame and a guide carriage movable along the guide rail, whereby rolling elements are arranged between a track of the guide rail and a track of the guide carriage, which rolling elements are accommodated in recesses of a rolling element cage.
Accordingly, in this embodiment the guide rail and the guide carriage comprise tracks facing one another, that is to say rolling surfaces for a plurality of rolling elements, which are arranged relative to one another at a predetermined distance by means of the rolling element cage. When moving the support device along the frame the rolling elements roll off on the one side on the track of the stationary guide rail and on the other side on the track of the movable guide carriage. The rolling element cage is carried along in the direction of the longitudinal displacement of the guide carriage. Accordingly, a roller bearing or rolling bearing of the guide carriage is provided. Preferably, the rolling element cage comprises a plurality of recesses with rolling elements evenly spaced apart in the longitudinal direction of the rolling element cage. The embodiment according to the invention of the guide devices, in particular, has the advantage that guidance of the support device on opposite longitudinal sides of the frame may be accomplished with a particularly small play, i.e. in particular essentially free of play. Advantageously, this allows to reliably prevent that a unilateral or off-center load of the table top during the deploying or stowing process causes any undesired deadlock or canting of the guide carriage. Thus, malfunctions of the folding table can be avoided. Furthermore, wear of the folding table is reduced. Thus, the maintenance or replacement intervals can be increased, whereby the costs for the use of the folding table can be reduced. In addition, it is possible to save weight. Finally, it is advantageous that the generation of noise upon deploying or stowing the folding table can be reduced.
Due to the precise guidance of the opposite guide carriages over the rolling elements, in a particularly preferred embodiment, the guide devices are arranged relative to one another without connection on opposite sides of the frame. Here, “relative to one another without connection” means that a rigid cross connection between the opposite guide devices is missing. Of course, the exception to this is the connection of the guide devices over a table top installed on the support device, which table top may extend across the width of the frame, transversely to the direction of the longitudinal displacement. Due to the rolling bearing of the guide carriages a deadlock of the guide devices due to unilateral load can be reliably prevented, also without a rigid connection between the guide devices, in particular without a connecting rod or connecting shaft. Thus, the overall weight of the folding table can be reduced essentially.
To reliably hold the rolling elements in the desired position, it is favorable if the rolling element cage is arranged between the guide rail and the guide carriage in such a way that the rolling element cage essentially travels half the distance of the guide carriage between the stowed position and the deployed position of the support device. Preferably, the rolling element cage is arranged essentially centrally between the tracks of the guide rail and the guide carriage. Accordingly, a movement of the guide carriage by a certain distance causes a movement of the rolling element cage by essentially half the distance of the guide carriage.
To adapt the rolling element cage to the linear movement of the guide carriage it is advantageous if, as a rolling element cage, an elongated profile element having opposite flanges is provided, on which the recesses for the rolling elements are formed. Preferably, the cross-section of the profile element is essentially constant in the direction of displacement of the guide carriage. The flanges of the profile element comprise recesses in the form of perforations, wherein the rolling elements are arranged.
To facilitate rolling off of the rolling elements, it is favorable if the tracks of the guide rail and of the guide carriage are curved in an arc-shaped, in particular in a circular-arc-shaped manner with regard to their cross-section. The cross-section refers to a plane perpendicular to the longitudinal displacement of the guide carriage.
According to an especially preferred embodiment the guide carriage is connected to the support device via a hinge joint, in particular a joint pin. The longitudinal movement (displacement) of the guide carriage can be transferred to the support device by the hinge joint. In addition, the hinge joint realizes the folding device, with which the support element of the support device is foldable from the deployed position to the use position.
To support the guide carriage precisely on the guide rail it is favorable if balls are provided as rolling elements.
Regarding a space-saving, constructionally simple and reliable design it is favorable if the guide carriage comprises a mount for the traction cable, whereby the guide carriage comprising the mount for the traction cable is movable (displaceable) along a guide groove provided on the frame. In this design, for this reason, the mounts for the traction cables are integrated in the guide carriages. For example, the mounts for the traction cables on the guide carriages can be designed by cylindrical recesses, in which each a cylinder provided at the end of the respective traction cable can be arranged, so that the traction cable is fixed on the guide carriage. Preferably, the guide carriages are essentially movable in a vertical direction along the guide grooves on opposite longitudinal sides of the frame. Advantageously, it is thus possible to design the frame in a particularly narrow manner. Thus, the space required for installing the folding table, for instance, in a side-panelling or armrest the passenger seat can be reduced or a broader support device can be used, by means of which the mount of the tabletop can be designed in a particularly stable manner.
When the linear drive element is arranged in the operating position in an essentially horizontal position on a lower frame element of the frame, the frame element essentially extending in a horizontal direction, the linear drive element can be accommodated on the frame in a space-saving manner.
To lift the support device with the table top into the deployed position the guide devices are preferably arranged on lateral frame elements essentially extending in a vertical direction, whereby the forward motion of the linear drive element, in particular, in the horizontal direction can be converted, by means of deflection pulleys of the cable pull device, into corresponding essentially vertical displacements of the guide devices along the lateral frame elements of the frame. Thus the cable pull device especially offers the advantage that the feed direction of the linear drive element may be different from the direction of displacement of the displacement device. This is why the drive and displacement mechanism can be accommodated on the frame in an especially space-saving manner. Preferably, the frame comprises a lower, essentially horizontal frame element, in which the linear drive element is arranged, and two lateral, essentially vertical frame elements, on which the guide devices for the support device are supported. Accordingly, the frame is essentially U-shaped, whereby the support device with the tabletop is deployable through the upper, open-end of the frame, prior to the movable part of the support device with the tabletop being laterally foldable into the use position.
According to a particularly preferred embodiment the cable pull device comprises at least one transmission roll to obtain transmission between the forward motion of the linear drive element and the displacement of the displacements device. The transmission ratio between the displacement of the linear drive element and the displacement of the displacement device preferably is between 2 and 5, in particular essentially 3. The force to be applied onto the displacement device by the linear drive element can be reduced by the transmission of the drive movement. Furthermore, existing, standardized springs or dampening elements may be used for the linear drive element due to the variably selectable transmission. Preferably, at least one, in particular exactly one transmission roll is provided for each side of the folding table. The transmission rolls are preferably coupled to the linear drive element in order to join in its linear motion. Thereby, the cable pulls with the transmission rolls form a pulley block.
It is particularly advantageous if a dampening element for dampening the movement of the linear drive element is provided. Thus, a uniform deploying process can be achieved. For example, a dampening mechanism can be integrated in the gas spring already.
According to a preferred embodiment a dampened stop is provided between the frame and the linear drive element. In addition to the uniform deploying process, due to the dampening element the deploying position can be smoothly achieved thereby, additionally further reducing any noise generation.